Multiple physical cells under a base station are called subsites (Subsite), which belong to different physical addresses respectively, but logically belong to the same cell. Every subsite has the same cell-level parameter configurations such as the number of carriers, frequencies, and channels. A multi-site cell technology refers to combining multiple subsites into one cell to reduce user handovers, reduce the number of frequencies used by the entire cell, and use fewer frequencies to cover a wider area. The multi-site cell technology is especially applicable to a scenario where the user quantity to be covered is definite but the traffic is moving, for example, high-speed rails, buildings, tunnels, bridges, and stadiums.
As the multi-site cell technology is widely applied, its feature of saving frequencies of users is increasingly valued. However, in the process of implementing the present invention, the inventor finds at least the following problems in using the multi-site cell technology:
Because fewer frequencies are used, for example, after three subsites under a base station combine into one cell, the number of used logical channels decreases to ⅓ of an original number, the terminals in different subsites occupy different logical channels. Once a logical channel is occupied, the logical channel is unavailable to terminals in all other subsites under the entire cell, which reduces capacity of the entire cell.